Volume 3, Issue 2-1, March 2015, Page: 1-6
Fatigue Life Extension Study in Cast Steel Railway Couplings Used in Freight Trains
Morgado T. L. M., Engineering Departmental Unit of Tomar Polytechnic Institute, Tomar, Portugal; CeFEMA - Center of Physics and Engineering of Advanced Materials, Lisbon University, Lisbon, Portugal
Received: Nov. 4, 2014;       Accepted: Nov. 6, 2014;       Published: Nov. 14, 2014
DOI: 10.11648/j.ijmea.s.2015030201.11      View  3398      Downloads  312
In this paper, fatigue life extension results from pre-existing surface defects in cast steel ASTM A148 90-60 of railway couplings, used in service in Portugal for coal transportation, are presented using two crack growth relationships (Paris equation and modified Paris equation). Fatigue lives were obtained and the results were discussed in terms of the threshold value for non-propagation cracks (modified Paris law) the initial value of the starting crack. It was found that for both crack growth relationships significant crack extension lives can be assumed. Therefore for these components and in this application damage tolerant procedure can be used with safety and this component can be kept in service provided appropriate inspection procedures are applied to detect and measure fatigue cracks. This will avoid early retirement from service of these components, since extension life can be assumed with safety.
Fatigue Crack Growth, Life Extension, Paris Law, Modified Paris Law, Railway Component
To cite this article
Morgado T. L. M., Fatigue Life Extension Study in Cast Steel Railway Couplings Used in Freight Trains, International Journal of Mechanical Engineering and Applications. Special Issue: Structural Integrity of Mechanical Components. Vol. 3, No. 2-1, 2015, pp. 1-6. doi: 10.11648/j.ijmea.s.2015030201.11
Paris PC, Gomez RE, Anderson WE. A rational analytic theory of fatigue. Trend Eng (1961); 13(1): 9–14.
Liu HW. ASME Trans J Basic Eng (1963); 85D(1): 116–22.
Paris PC, Erdogan F. Critical analysis of crack growth propagation laws. ASME Trans J Basic Eng (1963); 85D(4): 528–34.
Foreman R. G., Kearney V. E., Engle R. M.. Numerical analysis of crack propagation in cyclic-loaded structures. J. Basic Eng. (1967); 89: 459–464.
Ichikawa M. Probabilistic fracture mechanics investigation of fatigue crack growth rate. Statistic Research on Fatigue and Crack, ed. Tsuneshichi Tanaka et. al. London, New York: Elsiever Applied Science (1987); vol. 2: 71-89.
Bergner F., Zouhar G. A new approach to the correlation between the coefficient and the exponent in the power law equation of fatigue crack growth. International Journal of Fatigue 22 (2000): 229-239.
Schijve J. Fatigue of structures and materials in the 20th century and the state of the art. Int J Fatigue (2003); 25: 679–702.
Ritchie R. D.. Near threshold fatigue crack propagation in steels. Met. Rev. Review 145 (1979); No. 5 and 6: 205.
Infante V., Branco C. M., Brito A. S., Morgado T. L. M. A failure analysis study of cast steel railway couplings used for coal transportation. Engineering Failure Analysis, 10 (2003): 475–489.
BS 5447:1977 (1987). Methods of test for Plane Strain Fracture Toughness (KIC) of Metallic Materials. British Standard Institution.
ASTM E647-05. Standard Test Method for Measurement of Fatigue Crack Growth Rates. Developed by Subcommittee E08.06, Book of Standards Volume 03.01, WestConshohoken, USA.
Hertzberg R. W.. Deformation and Fracture Mechanics of Engineering Materials. 3rd edition. John Wiley & Sons Inc.. Canada 1989.
ASM Handbook. Volume 19: Fatigue and Fracture. 2nd edition. ASM International. USA. ISBN 10: 0-87170-377-7.
Ventura F.. Inconel 718 Fatigue Crack Propagation at High Temperature. Ph. D Thesis (in Portuguese). Coimbra University. Portugal, 1999.
Morgado T. L. M.. Structural Integrity of a Railway Component. Ph. D Thesis (in Portuguese). Lisbon University. Portugal, 2009.
Morgado T. L. M., Branco C. M., Infante V. .Reliability fatigue analysis of Steel Couplings used in railway transport f coal. Second International Conference on Material and Component Performance under Variable Amplitude Loading Proceedings volume II (2009), 715-22. ISBN: 978-3-00-027049-9.
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